Many-body Interaction of Oligomers: A Quantum Chemical Study

From last few years as per the modern society’s demand for improved telecommunications and data processing photonics - the use of light to acquire store process and transmit data - has become an active field of research. In this work We have also studied hydrogen bonding interactions in cyanamide and acetonitrile oligomers using many-body analysis technique using density functional theory (DFT) method. We have studied the cyclic and ladder type hydrogen-bonded cyanamide and acetonitrile oligomers using density functional theory with aug-cc-pvdz basis set. Among different levels of theory used here the geometrical parameters and vibrational frequencies at B3LYP/aug-cc-pvdz level are in good agreement with the experimental determinations. Cyclic structures are more stable than the ladder. The hydrogen bonds in cyclic oligomers are stronger than those for the ladder. However both structures are quantum mechanically stable with no soft vibrational modes. The nature of interactions between different molecules in dimer to pentamer is studied using many-body analysis approach.